A new patient arrived at the local health centre and the receptionist was taking down some details. “What is your age Mr. Jones?” she enquired. “I'm not telling you” came the reply. “We need to know for our records” said the receptionist sternly. “Okay, take the number 26 and double it and then add 14” said Mr. Jones.” ”That equals 66” said the receptionist. “Now take 66 away from that figure and what do you have?”" Mr. Jones retorted. “Zero” said the receptionist looking rather puzzled. “Exactl…